414 



RESEARCHES ON FUNGI 



pilear depression consists of netted gelatinous hyphae which ter- 

 minate above in a layer of clavate cells (Fig. 210). These clavate 

 cells are more club-shaped and less fimbriate than those which 

 bound the flesh above the gills. 



The spores are produced in considerable numbers when once the 

 pileus has begun to liberate them, and fairly thick white spore- 

 deposits were obtained on cover-glasses placed beneath the pilei 

 of fruit-bodies growing normally on Oleander leaves. 



Newly fallen spores were tested for germination. The spores on 

 some cover -glasses were covered with sterilised tap-water, those 



on other cover-glasses 

 with malt-agar, and 

 those on still other 

 cover-glasses with malt- 

 extract (2-5 grams malt 

 to 100 cc. water), and 

 the cover-glasses, with 

 their drops hanging 

 downwards, were set on 

 van-Tieghem cells con- 

 taining a little water. 

 The spores in the tap- 

 water and in the malt- 

 agar did not germinate, 

 but those in the malt-extract put out germ-tubes within 36 hours. 

 Stages in the germination of some spores are shown in Fig. 211. 



A pileus which was actively discharging spores was set in suc- 

 cession over two fresh wounds scratched in a Bryophyllum leaf, so 

 that many spores must have fallen into each wound. The leaves 

 were kept on very wet sand in a Petri dish covered with a bell- jar. 

 The air in the Petri dish must have been saturated with water 

 vapour. Nevertheless, the wounds healed up without becoming 

 infected. Whether or not, therefore, germinating basidiospores can 

 initiate the Coffee leaf-spot disease is still an open question. Since, 

 under natural conditions, the perfect fruit-bodies appear to be but 

 rarely developed, basidiospore infection, if it occurs at all, may be 

 very infrequent. 



Fig. 210. — Ornphalia flavida. A, surface view, and 

 B, vertical section, of the pileus-fie.sh above the 

 stipe and below the central umbilicate de- 

 pression : a, clavate fimbriate cells ; b, muci- 

 lage ; c, netted hyphae. Drawn by A. H. R. 

 Buller and Ruth Macrae. Magnification, 467. 



